1. Field of the Invention
The present invention relates to an apparatus for determining the time taken for sound energy to cross a body of fluid in a pipe.
2. Related Art
The time taken for sound energy to cross a body of fluid in a pipe of known linear dimension in the direction of propagation of the sound energy provides a measure of the speed of sound in the fluid, and that can be used to determine a parameter of the fluid in the pipe, for example, the density of the fluid in the pipe. The determination of a parameter of a fluid may permit the identification of the fluid. For example, a measure of the speed of sound in a fluid which may be either beer or water may be used to distinguish between the fluids. Therefore, an apparatus for classifying fluids may be, in effect, an apparatus for measuring the speed of sound in the fluid.